/**
 * Created by Administrator on 2016/4/3.
 */
import java.util.*;
class Student
{
    private String name;
    private String number;
    Student(String name, String number)
    {
        this.name = name;
        this.number = number;
    }

    @Override
    public String toString()
    {
        return String.format("(%s,%s)",name,number);
    }
}
public class Students {
    public static void main(String[] args)
    {
        Set students = new HashSet();
        students.add(new Student("Justin","B835031"));
        students.add(new Student("Monica","B835032"));
        students.add(new Student("Justin","B835031"));
        System.out.println(students);
    }

}

